Photo below shows the brake lever in the released position. In this position it will be tucked under the “dash” of the trike and partially hidden from view once the dash is installed.

The final Photo shows the brake lever in the engaged position. When engaged the level protrudes out from under the dash and will be easy to spot to remind the rider to release before engaging the motor.

My Kelly KLS7230S controllers are capable of providing variable regeneration. To alter the amount of regeneration the controllers need a 0-5 volt signal. The simplest way to provide that variable signal would be with a common twist or thumb throttle located on the handlebars. But I felt a second twist throttle, or even a thumb throttle would be confusing and sort of counter intuitive. I felt a better solution might be to mount a typical brake lever on left side handlebar and then run its cable to a thumb throttle mechanism located toward the rear of the trike. My thinking is that this will provide the more natural “feel” of a traditional motorcycle hand brake when the regen is activated.

Unfortunately, the “throw” of most brake levers is not quite long enough for the cable to pull the thumb throttle from the zero position to the full throttle position. As a result, the controllers would not receive a signal for maximum regeneration. To remedy this situation I needed a way to “gear up” the cable so the brake lever movement can provide a longer pull.

To do this I am using a freewheel body from an old six speed cassette stack. Note that the freewheel body has two grooves (arrows), one larger than the other. By running the incoming brake lever cable around the smaller diameter groove and the outgoing thumb throttle cable around the larger groove, the pull of the brake lever can be multiplied enough to move the thumb throttle lever from its zero position to its 5 volt (maximum) position. The six speed freewheel body is threaded onto the wheel hub allowing it to freely rotate while still being held in the proper position.

Only the threaded “cassette” side of the wheel hub is needed, so the balance of the hub is cut off leaving the hub disk and threads as a mounting platform for the freewheel body.

The hub disk is ground flat on the back side.

To guide the cable from the brake lever onto the groove of the free wheel, an old brake lever handle is cut apart saving the guide (arrow) and a portion of the lever which is drilled for mounting bolts. A stock brake lever is shown on the right and the cut down portion use for the guide is shown on the left.

With the freewheel body unscrewed and removed we can see the threaded mount of the hub disk. Two 1/4″ holes (arrows) are drilled in the hub disk for mounting.

The components are laid out on 3/16 x 3″ wide flat stock. On the left is the “guide”, in the middle is the freewheel body “gear multiplier” and on the right is the thumb throttle. (Photo 6) When everything appears to be in alignment for smooth operation, the mounting points for each component are marked and the flat stock can be cut to the appropriate length and appropriate holes drilled for mounting the guide and the hub disk. The thumb throttle is mounted on a short length of handlebar tubing which is welded to the 3″ flat stock.

The components attached to the base. The thumb pad of the throttle will have a small hole drilled through the center for inserting the cable.

To secure the end of each cable in the freewheel body groove a “bridge” is welded over the top of each groove. The cable is then inserted into the groove and under the bridge. To insure the weld does not go all the way to the base of the groove, making it impossible to fit the cable under it, a large diameter copper wire is placed in the groove while the bridge is tacked in place. The copper will not bind to the weld and can be pulled out once the weld has cooled. The cable can then be threaded under the bridge, tightened and a stop crimped to the cable. [Note: Variable Regen continued in next post.]

Note that the cable from the brake lever to the freewheel body “gear” needs to be adjustable in order to get the cable tight. Instead of crimping on the stop, a cable ferrule is used and a small screw inserted into the open end of the ferrule and tightened securely. Not a particularly elegant solution, but it works and the cable can be readjusted at any time.

The thumb throttle has its own spring to return it to the zero position but to insure the throttle does not hang up due to friction in the cable or gear mechanism, an additional spring (arrow) is attached to the back side of the throttle lever.

The variable regen mechanism is then bolted to the trike frame. With the cables attached the left hand brake lever now operates the thumb throttle which, in turn, engages the regeneration function of the two Kelly controllers on a variable basis. The harder you squeeze the brake lever, the greater the amount of regeneration AND the greater the amount of braking effect created by the regeneration.

Unfortunately, the “throw” of most brake levers is not quite long enough for the cable to pull the thumb throttle from the zero position to the full throttle position. As a result, the controllers would not receive a signal for maximum regeneration. To remedy this situation I needed a way to “gear up” the cable so the brake lever movement can provide a longer pull.

Unfortunately, the “throw” of most brake levers is not quite long enough for the cable to pull the thumb throttle from the zero position to the full throttle position. As a result, the controllers would not receive a signal for maximum regeneration. To remedy this situation I needed a way to “gear up” the cable so the brake lever movement can provide a longer pull.

If you like, ProblemSolvers makes a small pulley to fix this kind of issue with brakes, that would also probably work for your situation, called a Travel Agent...

My "default" solution is usually to look around the shop and see what piece of old junk might work to solve a problem. But thanks for the link etc, it provides another good option for folks to consider. I also received another possible alternative, using a small lever with an offset fulcrum to multiply the throw distance. So lots of ways to skin this cat.

Good for Kelly, old types only did 0-5V.
Is the V range adjustable for variable regen?

The throttle input is adjustable for range and can be programmed into the controller. But I don't believe the variable regen input is adjustable, at least I couldn't find anything in the setup info to do that. That's why I went with "gearing up" the cable. The build is not quite to the point of actually doing the programming yet so I might discover something when I hook up my PC to the controller and start snooping around.

To protect the electrical components and wiring for the trike, body panels will be made to enclose the battery and electronics compartment. A body panel will also be created to serve as a “dashboard” for mounting switches and to enclose wiring at the front of the trike. The body panels will be made using lightweight and relatively inexpensive aluminum flashing. Used alone, flashing is too thin and would reveal bumps, bows and other distortions in the metal. So I am using a technique I have used to make dashboards and other panels for some of the hot rods I have built. Each panel has a “core” made from 1/8″ plywood. The aluminum flashing is then cut and glued to the core to form a solid, stable surface. Note that this technique can only be used on flat surfaces or surfaces curved in only one direction. It can not be used for compound curves or compound/complex curves.

Each panel section core is measured and then cut from 1/8″ plywood. Photo below shows all the plywood panel cores for the chopper trike.

Aluminum flashing is cut to the outer shape of each panel with ½” to 5/8″ of extra material on all edges. Do not cut out irregular shapes of the panel at this point.

Apply DAP Weldwood contact cement to the front of the plywood and the rear of the aluminum. Dry for the recommended time period and attach the aluminum panel to the plywood panel making sure to leave ½” of flashing extending beyond the plywood on all edges.

From the plywood side, a simple panel will look something like the Photo below. Note that none of the irregular shapes have been cut out at this point.

On the flashing side the panel will look like the Photo below.

Using a good set of tin snips or metal cutting shears cut each outside corner as shown in Photo below.

Inside corners are cut as shown in the Photo below. Once all corners have been cut, apply contact cement to the exposed surfaces and to the back side of the plywood, wait the appropriate time, and then fold the edges of the flashing over the edges of the plywood and press firmly in place on the back side of the plywood.

This Photo shows all of the completed plywood core body panels for the chopper trike.

The “dashboard” panel is installed with machine screws for easy removal.

The other body panels are attached using nylon push type fender rivets. These rivets are most commonly found in automotive application for both interior and exterior fastening. The rivets can be removed once they are in place but they do sometimes break off or become difficult to remove. So if you know a body panel is going to be on and off a number of times it might be better to use a different type of fastener, such as a machine screw. Also, some may want to choose a different fastener if the do not like the “look” of the nylon rivets.

Photo below is a close up of an installed fender rivet.

The top panels of the battery box lid are riveted in place.

Access holes for electrical wiring are cut in the body panels with a hole saw.

Rubber grommets are used to enclose the holes and protect the wiring.

The front view of the completed body panels. Note that the two openings at the upper left and upper right of the deck lid are purposely left uncovered to allow air flow to help cool the controllers and the battery box.